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2 E. B M O O L 0 H G A ELEOTRIU LAMP.

Patented Feb. 7,1882.

N. PETERS. Phnloillhngmpllar. Washmgto 2 Sheets-Sheet 2 A. G. HOLUOMBE.

(No Model.)

ELECTRIC LAMP.

Patented Feb. 7,1882.

zinesses,

UNITED STATES PATENT OFFICE.

ALFRED G. HOLCOMBE, OF DANIELSONVILLE, CONNECTICUT, ASSIGNOR TO THE STANDARD ELECTRIC LIGHT COMPANY, OF NEIV YORK, N. Y.

ELECTRIC LAMP.

SPECIFICATION forming part of Letters Patent No. 253,205, datedFebruary '7, 1882.

Application filed March 1, 1881. (No model.)

To all whom it may concern:

Be it known that I, ALFRED G. HOLCOMBE, of Danielsonville, Windham county, State of Connecticut, have invented certain new and useful Improvementsiu Electric Lighting Apparatus, of which the following is a specification.

'In the electriclightingapparatus which forms the subjectmatter of this application the elec- 1o tric currentisdivided into two circuits, in each of which is an electromagnetic device. The one is for operating the feed mechanism to allow the upper carbon to feed down to the lower carbon. This circuit is always in the main line from the electrical generator, whatever number of lamps are in single circuit, so that when any one ofthe lamps is inoperative the continuity of the main line is unbroken. The second circuit of the lamp comprisesthe carbons and an elec- 2o tro-magnetic arrangement adapted to depress the lower carbon to form the are between the ends of the carbons. The proportional resistances of the two circuits is such that when the are adapted to the current is formed the cur- 2 5 rent that passes through the feed-regulating magnet isinsufficient to release the upper carbon; but the slightestincreasein the length of the are (which means an increase in the resistance of the circuit through which it is supplied) 0 changes the ratio of the conductivity of the two circuits by raising that of the feed-circuit. Consequently a greater proportion of the current passes through it and actuates the electromagnetic device to allow the upper carbon 3 5 to gradually fall until the arc is again of normal length and resistance. By this division of the current to actuate the independent carbon-feeding and arc-producing devices each circuit is so sensitive to the slightest change of the conductivity of the other circuit that the upper carbon feeds with a continuously steady motion, and no fluctuation in the light is produced, except what is due to impurities in the carbons, which fluctuations are im- 5 material with carbons as now made. So I am enabled by the application of the above principle of dividing the current through the lamp, by the means and in the mannerhereinafter described, to eliminate from electric-arc lights all unpleasant fluctuations and sudden changes,

which embodiment of the principle in a practical apparatus I will now describe by referring to the accompanying drawings, in which Figure 1, Sheet 1, is a front elevation of my improved electric lighting apparatus. Fig.2, Sheet 1, is an end elevation of the same, and Fig. 3, Sheet 2, shows a modification by which the apparatus is adapted to operate with-a toand-fro current.

The two carbon rods to and a are held in the sockets b and'b. These sockets have taper holes, thereby forming a guide and bearing for the ends of different sizes of carbons, and they are provided with three set-screws,'b b radially arranged, so that the carbon rods are firmly griped by them, and by their adj ustment the ends ofthe carbon rods may be set directly opposite one another. The socket b of the upper carbon, (1, is secured to the lower end of the vertical sliding rod c, provided with the rack 0, into which meshes the pinion 0 fastened on the'shaft of the gear-wheel d, and into the gear-wheelcl meshes the pinion d, fastened onto the shaft of the brake-wheel c. The periphery of this brake-wheel c is smooth, and on it bears the shoe 0, carried by the lever], pivoted at fto downward-prey ecting studs on the top plate, 9, which, with the bottom plate, g, and rods g 9 constitute the frame-work of the upper part of the lamp. The spring h, connected to the outer end of the leverf, and pro- .vided with the adjusting-nuts h, causes the shoe 6 to bear with sufficient pressure on the brake-wheel e to prevent the rod 0 and carbon a from feeding downward. The other end of the lever f carries the core i of the axial magnet i, which, when traversed by an electric current, draws the core within the magnet i, and releases the pressure of the shoe 0 from the wheel 6 against the action of the spring h, 0 and so allows the rod 0 to feed downward.

In this class of feeding device, to insure a steady and uniform movement of the carbon rod, I havefound it essential that the bearingsurface of the shoe on the periphery of the 5 brake-wheel should be limited in extent; in fact, a dull knife-edge is all that is required; and it is also essential that the movement of the core or armature of the operating-magnet should be limited to what is necessary to just which the current leaves the lamp, as indicated free the brake-wheel of the shoe, so that the magnet may instantaneously actuate the brake in response to the smallest variation of the current passing through it, and at the same time be prevented from moving the shoe any great distance from the brake-wheel, which, if it is allowed to do, the carbon will fall farther than is necessary to bring the arc to its normal re- I sistance before the shoe can be brought to bear on the brake-wheel to overcome the momentum of the carbon.

The cause of the constant. and unpleasant fluctuations of the arcs of electric lamps as heretofore made, in which the upper carbon moves by gravity to compensate for the consumption of the carbons, is that no such perfect control of the carbon-feed has been had.

To limit this movement of the shoe I provide a set-screw, 0 passed through the top plate, 9, to act as a stop for the lever f; or it may be placed in any other convenient position-as, for instance, in the end of the leverf-to butt against the top plate, 9.

One end of the coil 1" is connected to the binding-post by which the current enters the lamp, and the other end to the frame 9 g, which is connected to the binding-post j, by

by the arrows or or. The postj and frame 9 g are on the nonconducting plate 7., and at its ends are secured the tubes l l, which are joined together at their lower ends by the bar V, in the center of which is secured the arc-producing device, consisting of the axial magnet on, placed in a metal case, and core m, on the upper end of which is secured the lower-carbonholding socket b.

The core m and socket b and carbon a are upheld by the spring a. The binding-post j is connected to the coil of the axial magnet on by the insulated conductor 0, passing down inside of the tube Z and under the bar 1 The inner end of the coil is soldered to the case of the magnet, the core m and the spring a acting as conductors to allow the current to pass to the carbon (1 after traversing the coil m,- and to insure a perfect connection I propose to solder or otherwise secure one end of the spring a to the metal case of the coiland the other end to the under side of the socket b, so that this supporting-spring is made to act as the connecting-conductor between the carbonholder and its actuating electro-magnet.

The arrows 00 00 indicate the direction of the arc-producing current. The spring g on the top plate, g, bearing against the rod 0, insures a perfect electrical connection between the upper frame, g g, and the rod 0.

From the foregoing description it will be observed that the electriccurrent, when the conductors of the generator are secured in the binding-posts j and j, is divided and passes through two independent circuits, 00 and w, the one, 00, including the magnet i, and which is always closed, and the other, 00, including the magnet m and carbons a and a, and which is closed only when the carbons are in contact, or when the arc is produced between their ends. Assume the lamp in condition to operate with the upper carbon, (1, held up from the lower carbon, a, by the pressure of the brake-shoe c on the wheel 0, and placed in circuit with the generator. The whole of the currentpasses through the magnet i, which instantly releases the brake-wheel e and allows the rod 0 and carbon a to fall until arrested by the carbon a. The circuit through the magnet m and the carbons is thereby closed, and the greater part of the current passes through the magnet on and the carbons, as the resistance of the circuit 00, including them, is much less than that of the circuit a;, including the magnet 43. The magnet m now draws down the core at and the carbon a against the action of the spring a, and the electric arc is produced between the ends of the carbons, the upper carbon, a, being held by the brake 0 c as the spring h is adjusted to oppose the inductive magnetic action of the current which now passes through the magnet i. No particular adjustment of the spring a is necessary. The action of the current passing through the magnet m draws the core on down until the pressure on the spring a counteracts the inductive action of the current on the core m, and if the arc is then greater than it should be the upper carbon continues to fall to reduce the arc to its normal length, because then the arc resistance increases and a greater proportion of the current passes through the magnet 'i, which instantly raises the shoe 0 clear of the brake-wheel c. This same action takes place as the carbons gradually consume, and the carbon a feeds with a practically steady continuous movement, and only so fast as the carbons are consumed.

Any number of lamps may be worked in single circuit, and the extinction of any one or any number of such lamps in the circuit in no wise affects the proper working of the others, as the brake-magnet circuit virtually forms a part of the main line for the current. To enable this principle to be employed with a toand-fro current, I substitute two solenoids, as described in the application No. 6,480, filed by me April 2, 1880, for the magnet and core in m, and two fiat parallel coils, as described in application No. 26,642, filed by me February 21, 1881, for the magnet and core 5 t, as shown at Fig. 3, the general construction being the same as that shown in Figs. 1 and 2.

The lever f is located under the brake-wheel e, and the shoe is pressed againstit by the adjustable flat spring 7L2. One of the flat coils of wire,r, is fastened to the lever f, and the other one, r ,to the base-plate g, and they are joined up, so that a to-and-fro current in passing through them will cause a mutual attraction between them. The inner solenoid, s, of the are-producing device is connected at one of its ends to the carbon-holding socket b, and at the other end to the supporting-spring t, which is adjusted by the set-screw 1., the lower end of the spring being connected to one end of the outer solenoid, s, which at its other end joins the conductor 0. The spring t is adjusted by the set-screw Two solenoids may be used in place of the two fiat coils, or the coils may be used in place of the solenoids.

It is obvious that instead of the two axial magnets shown in 'Figs. 1 and 2 ordinary electromagnets and armatures may be used; and it is also obvious that the teed-releasing magnet and arc-producing magnet maybe arranged in one electric circuit.

Having now described my invention, what 1 claim, and desire to secure by Letters Patent,

1. In a feeding device for electric lighting apparatus, in combination, a brake-wheel actuated by the gravity of the carbon-holding rods by means of suitable connecting-gearing, a lever provided with a narrow-edge contactshoe, caused to bear on the periphery of the brake-wheel by means of an adjustable spring, a stop device to govern the extent ofmovement of the lever, and an electro-magnet adapted to move the lever away from the brake-wheel and against the stop device, substantially as and for the purpose set forth.

2. In an electric lighting apparatus, an axial magnet included in the branch circuit of the lamp which is always closed, the movable core connected to the brake-lever, a brake-wheel actuated by a rack on the upper-earbon-holding rod, an adjustable spring for causing the lever to bear on the brake-wheel, and the upper carbon adapted to feed down by gravity when the axial magnet raises the lever oi? the brake-wheel, in combination with the lower carbon, its holder and supporting-spring, the core of an axial magnet, and the axial magnet, the whole of which,with the upper carbon, constitutesthemaincircuitofthelampthroughwhich apart of the electric current flows to form the are between the ends of the carbon-rods when the lower carbon is depressed by the action of the axial magnet on its core, substantially as and for the purpose hereinbefore set forth.

In witness whereof I have hereunto set my hand this 26th day of February, A. D. 1881.

ALFRED G. HOLCOMBE.

Witnesses:

LA FAYETTE H. DE FRIESE, H. D. WrLLrAMs. 

